8148930: Incorrect erasure of exceptions in override-equivalent dual interface impl

Summary: Before computing intersection of thrown types, javac must make sure type variables come from the same set.
Reviewed-by: mcimadamore

langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Resolve.java

@@ -4043,7 +4043,12 @@ public class Resolve {
                         found = false;
                         break;
                     }
-                    allThrown = chk.intersect(allThrown, mt2.getThrownTypes());
+                    List<Type> thrownTypes2 = mt2.getThrownTypes();
+                    if (mt.hasTag(FORALL) && mt2.hasTag(FORALL)) {
+                        // if both are generic methods, adjust thrown types ahead of intersection computation
+                        thrownTypes2 = types.subst(thrownTypes2, mt2.getTypeArguments(), mt.getTypeArguments());
+                    }
+                    allThrown = chk.intersect(allThrown, thrownTypes2);
                 }
                 if (found) {
                     //all ambiguous methods were abstract and one method had

langtools/test/tools/javac/generics/inference/CheckNoTimeoutException.java

+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * @test
+ * @bug 8148930
+ * @summary Verify that there is no spurious unreported exception error.
+ * @modules java.sql
+ * @compile CheckNoTimeoutException.java
+ */
+
+import java.util.Collection;
+import java.util.List;
+import java.util.ArrayList;
+import java.util.concurrent.TimeoutException;
+import java.io.*;
+import java.sql.SQLException;
+import java.sql.SQLTransientException;
+
+class CheckNoTimeoutException {
+
+    interface V {List<?> foo(List<String> arg) throws EOFException, SQLException, TimeoutException;}
+    interface U {Collection foo(List<String> arg) throws IOException, SQLTransientException;}
+
+    //SAM type ([List<String>], List<String>/List, {EOFException, SQLTransientException})
+    interface UV extends U, V {}
+
+
+    private static List<String> strs = new ArrayList<String>();
+    void methodUV(UV uv) {
+        System.out.println("methodUV(): SAM type interface UV object instantiated: " + uv);
+        try{
+            System.out.println("result returned: " + uv.foo(strs));
+        }catch(EOFException e){
+            System.out.println(e.getMessage());
+        }catch(SQLTransientException ex){
+            System.out.println(ex.getMessage());
+        }
+    }
+}
\ No newline at end of file

langtools/test/tools/javac/generics/inference/IntersectThrownTypesTest.java

+/*
+ * @test /nodynamiccopyright/
+ * @bug 8148930
+ * @summary Incorrect erasure of exceptions in override-equivalent dual interface impl
+ * @compile/fail/ref=IntersectThrownTypesTest.out -XDrawDiagnostics IntersectThrownTypesTest.java
+ */
+
+public class IntersectThrownTypesTest {
+
+    interface S1 {
+        <K extends Exception> void run(Class<K> clazz) throws K;
+    }
+
+    interface S2 {
+        <K extends Exception> void run(Class<K> clazz) throws K;
+    }
+
+    interface S extends S1, S2 {}
+
+    public void foo(S1 s) {
+        s.run(java.io.IOException.class);
+    }
+
+    public void foo(S s) {
+        s.run(java.io.IOException.class);
+    }
+
+}

langtools/test/tools/javac/generics/inference/IntersectThrownTypesTest.out

+IntersectThrownTypesTest.java:21:14: compiler.err.unreported.exception.need.to.catch.or.throw: java.io.IOException
+IntersectThrownTypesTest.java:25:14: compiler.err.unreported.exception.need.to.catch.or.throw: java.io.IOException
+2 errors